Saphenous Veins: Great and Small – Anatomy, Tributaries, and Clinical Use

The great saphenous vein (GSV) and small saphenous vein (SSV) are the principal superficial veins of the lower limb. They are the longest veins in the body and critical for venous return, bypass grafts, and sclerotherapy.

Great Saphenous Vein (GSV)

• Origin: Dorsal venous arch of foot (medial marginal vein).
• Course: Anterior to medial malleolus → medial leg → posterior to knee (adductor canal/Hunter's canal) → saphenous opening (fossa ovalis) → femoral vein (saphenofemoral junction, SFJ).
• Length: ~50–60 cm.
• Key Tributaries: Posterior arch vein (Leonardo), anterior/posterior tibial veins, accessory saphenous veins, perforators (Boyd's, Dodd's, Hunterian).
• Valves: 10–20; prevent reflux. SFJ valve critical.

Small Saphenous Vein (SSV)

• Origin: Dorsal venous arch (lateral marginal vein).
• Course: Posterior to lateral malleolus → lateral calf → between gastrocnemius heads → popliteal fossa → popliteal vein (sphenopopliteal junction, SPJ). Variable termination.
• Length: ~30–40 cm.
• Tributaries: Giacomini vein (thigh extension to GSV), sural nerve runs alongside.

Clinical Significance

• Varicose Veins: GSV/SSV reflux → tributary dilation. CEAP classification. Treat: endovenous ablation (RFA, laser), MOCA, cyanoacrylate, sclerotherapy, phlebectomy.
• Coronary Artery Bypass Graft (CABG): GSV is gold standard conduit (long, size match, easy harvest). Endoscopic harvest standard.
• Peripheral Bypass: Femoropopliteal, infrapopliteal.
• IV Access: Cutdown at ankle (emergency).
• Saphenous Nerve Block: Anesthesia for medial leg/foot (nerve runs with GSV).

Duplex Ultrasound Mapping

Pre-procedure standard: diameter, reflux duration (>0.5 s pathological), perforator competence, deep vein patency, variant anatomy (duplication, absent SFJ/SPJ).